Mouth bacteria may be altered by pesticide exposure

MONDAY, Nov. 28, 2016 -- Pesticide exposure may change the makeup of bacteria in the mouths of farm workers, a new study finds.

Researchers at the University of Washington
analyzed swabs taken from the mouths of 65 adult farm workers and 52
adults who didn't work on farms. All lived in Washington's Yakima
Valley.

The farm workers had higher blood levels of
pesticides, and greater changes in their mouth bacteria than non-farm
workers, the study found.

The most significant finding was in farm workers who had the organophosphate pesticide Azinphos-methyl in their blood.

In this group, researchers found significantly
reduced quantities of seven common groups of oral bacteria. Among those
was Streptococcus, which first author Ian Stanaway called "one of the
most common normal microbiota in the mouth." He's a doctoral candidate
in environmental toxicology.

Stanaway noted that previous studies have
found that "changes in species and strains of Streptococcus have been
associated with changes in oral health."

The changes noted in this new study persisted
into the winter, long after the growing season when pesticide use is
highest, the researchers said.

The results were published recently in the journal Applied and Environmental Microbiology.

With this discovery, "the challenge becomes,
what does this mean? We don't know," principal investigator Elaine
Faustman said in a journal news release. Faustman is a professor in the
university's Department of Environmental and Occupational Health
Sciences.